Composite films in which various films are bonded with a laminating adhesive are widely used in various industrial fields.
In particular, a composite film in which, for example, a plastic film, and a metal foil or a metal deposited film are bonded with a laminating adhesive is excellent in light shading properties and gas and liquid barrier properties; and is widely used as various materials that require such barrier properties.
As laminating adhesives for adhesion of composite films, a two-component curable adhesive composed of a polyisocyanate component and a polyol component is widely known.
Recently, in view of reduction in environmental burden and improvement in working environment, development of solventless laminating adhesives containing no organic solvent but containing a polyisocyanate component and a polyol component has been examined (for example, see Patent Document 1 below).
Furthermore, using the above-described solventless laminating adhesive, for example, a composite film excellent in barrier properties can be produced by laminating a plastic film such as a polyethylene terephthalate (PET) film to an aluminum vapor deposited film.